So the new novel coming out - Halo: Shadow of Reach takes us back to Reach, more specifically Castle base. So I have some theories related to past revelations about Infinite and what the novel might contain.
A short while ago there was an uncovered Easter Egg uncovered from the Discover Hope trailer where we got an audio clip of what sounds like Cortana saying - “This… This is apart of me. I don’t know how but it is me.”
We also know from the trailer that the chips serial number is that same as Cortana’s just one iteration higher - ends in 30 rather than 29.
Now in the novel we are going back to Castle base… Here’s what I suspect. Blue team is going there to recover some means of creating a new Cortana - maybe a clone of Halsey’s brain or a replica of Cortana’s old data from her initial creation - Something - that will allow for the creation of a new Cortana model but kind of a blank slate.
Going a little further, if this is true, I suspect we will be traveling around Zeta Halo collecting and reintegrating fragments of Cortana with the newly created Cortana from what is found in Castle base.